Should you drink more coffee? Should you take melatonin? Can you train yourself to need less sleep? A physician’s guide to sleep in a stressful age.

If coffee does have an effect on longevity, it is likely a result of something more global than the potential effect of antioxidants—such as the fact that constant exposure to caffeine, even at low levels, suppresses appetite (in a world where most people eat more than is ideal). Or that it encourages social interaction—it inclines us to go out and do things with people—which itself is generally beneficial to health.

A new report from Australia’s Climate Institute says coffee production worldwide is in danger because of climate change. It cites a study that says “hotter weather and changes in rainfall patterns are projected to cut the area suitable for coffee in half by 2050.”

.. “Coffee depends on a lot of water,” says Perseu Perdoná, an agronomist with the local coffee cooperative. And coffee plants are already sensitive to temperature. “Climate change is happening,” he tells me, “we can see it. Add to that deforestation, which means the ground can’t retain water when it rains.”

He fears that in the near future, unless something drastically changes, coffee will disappear from this region.

.. “The rivers have run dry,” he says. “Even in the city, we have water rationing — one day we have water, one day we don’t. We never expected this.”